Automotive internal combustion engine fuel systems may use connectors to couple components of the fuel line. For example, connectors may be used to join fuel lines with system components such as engine fuel rails, fuel tanks, evaporative emission control canisters, etc. Likewise, connectors may be used to join lines for pumping hydraulic fluid. Fuel lines can be used to transport liquid fuel from the fuel tank to a fuel injector and to transfer fuel vapor to an evaporative emission control canister. Due to their location, such connectors may be subjected to stress, such as during installation, service repair procedures, diurnal heating/cooling, and due to impact from a vehicle crash. When fuel line connectors are subjected to external and/or internal stresses, the stress may be concentrated at the joints of the connector, leading to localized leaks in the fuel line. This can cause leakage of liquid fuel or fuel vapor which can degrade emissions.
One example fuel line connector is shown by Ingram in U.S. Pat. No. 7,681,586. Therein a double walled connector is described with three portions. The upper and lower portions are inflexible and clamp to outside components. A middle portion coupled to the upper and lower portions is flexible.
However, the inventors herein have recognized potential issues with such connectors. As one example, despite having flexibility, the connector may still have restricted rotational ability. Also, the connector of Ingram is designed for use in fuel dispenser sump connection systems, such as those used in gas stations. As a result, the connectors of Ingram may be difficult to use in tight-fit locations, such as those in fuel lines of internal combustion engines coupled in vehicles. Due to insufficient flexibility and rotatability of the connectors, external or internal stress on the fuel lines can be significant, leading to localized leakages.
The inventors herein have developed a connector configuration that may include sufficient degrees of freedom by which the issues described above may be at least partly addressed. One example of such a connector comprises: an upper and a lower portion physically coupleable to a middle portion, the lower portion comprising a plurality of springs in direct contact with the middle portion, where the middle portion comprises a plurality of spherical bearings to enable rotation between the upper and lower portions. In this way, connector systems may be designed to have flexibility and multiple degrees of freedom.
As an example, a flexible connector may be designed for use in fuel lines and hydraulic lines that can stand a high level of internal and external stress due to its ability to rotate and flex. The flexible connector consists of three separate components, an upper, a lower and a middle portion. The upper and lower portions are coupleable to the middle portion. Flexibility is provided by a plurality of spherical bearings and springs coupled to the middle and lower portions of the connector. The upper engagement portion may consist of a fitting nozzle with geometrical features designed for easy self-engagement and mating with an external part, such as a fuel line connecting to an engine, fuel tank, etc. In addition, the upper portion may be designed to prevent back sliding and detachment from other parts while maintaining internal pressure and creating an insulation pocket. For example, the upper portion may comprise a nozzle fitting with a plurality of angled cylindrical rings and ramps facing away from an extreme end of the nozzle. The upper portion may be fitted with a rubber seal to further reduce leaks. The middle portion may comprise a plurality of spherical bearings, evenly dispersed along an inner circumference, in order to improve flexibility and to enable rotation between the upper and lower portions. The top surface of the lower portion may comprise a plurality of compression springs in direct contact with the middle portion. The springs may be used to control the engagement of the three portions and hold the connector system in place during rotational movement within a defined position. The bottom part of the lower portion may comprise a twist-lock mechanism with defined openings and geometrical slots designed to align and join the connection system to a fuel system component.
In this way, by designing a three component connection system consisting of compression springs and spherical bearings, flexibility can be achieved for fuel line connectors. The spherical bearings allow the upper and lower portions to rotate with respect to one another about an axis of rotation. The flexibility to rotate within their defined positions reduces force concentration during internal and external stresses and enables the connection system to overcome such stresses without localized leakages. The geometrical features allow for prevention of leakage and improved mating with external parts. The lower portion including a twist-lock connector helps couple the connection system to a fuel system component. Such flexible connectors may also be used in hydraulic systems. The technical effect of using flexible connectors is that adverse effect and leakages caused by internal or external stresses on fuel lines can be reduced significantly. By including geometrical features, the connector may allow for self-engagement and smooth coupling with external parts. As a result of the improved flexibility and increased degree of rotation, such connectors may be used in a wide variety of fluid lines. In addition, such connectors may be compatible with different vehicle designs and may be easy to service. In this way, connector systems may be designed to be able to withstand internal and external stresses in the fuel line. In addition due to the compact nature and functionality such connectors may be used in tight locations such as fuel systems in internal combustion engines.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.